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Hot flashes at menopause may signal a lower risk for heart attacks and stroke

Hot flashes at the start of menopause may be a good sign for your heart. (Jose J. Santos / Los Angeles…)

Hot flashes and night sweats at menopause are uncomfortable and annoying to many women. But they are also associated with a reduced risk of future heart attacks and strokes, researchers reported Thursday.

Hot flashes, which doctors call vasomotor symptoms, are a major issue in women's health because there are so few effective remedies to relieve them. In recent years, however, some studies have suggested that hot flashes and night sweats may also be a sign of potential cardiovascular problems. The idea is that hot flashes may be a response to some type of dysfunction in blood vessels that could also raise the risk of heart attack and stroke.

However, a new study, published in the journal Menopause, suggests that idea is an over-simplification. Researchers analyzed data from 60,000 post-menopausal women who were part of the Women's Health Initiative Observational Study. They found that the timing of hot flashes appears to matter greatly. Women who had hot flashes or night sweats at the start of menopause were actually at a slightly lower risk for stroke, heart disease and death compared with women who never had hot flashes or night sweats. The risk reductions were 17% for stroke, 11% for heart disease and 11% death.

"It is reassuring that these symptoms, which are experienced by so many women, do not seem to correlate with increased risk of cardiovascular disease," Dr. Emily Szmuilowicz, a co-author of the study from Northwestern Memorial Hospital in Chicago, said in a news release.

However, women in the study who did not have hot flashes or night sweats at the onset of menopause but developed them later in menopause (they were having symptoms at an average age of 63) had a 32% higher risk of heart attack and a 29% higher risk of stroke.

Women who developed hot flashes and night sweats at the onset of menopause and continued to have them into later menopause had no increased or decreased risk.

It's not clear why hot flashes at the time of menopause are linked to a lower risk of cardiovascular events. But the authors wrote: "One possibility is that perimenopausal vasomotor symptoms represent a physiologic response to the normal perimenopausal hormonal fluctuations, and the absence of these symptoms may signify a blunted vascular response to these hormonal changes."

Far fewer women develop hot flashes years after menopause begins, the authors note. But more research should be devoted to the link between late symptoms and cardiovascular risk. Hot flashes occurring well after menopause may be a marker for instability in blood vessels, they wrote.